Agronomy Library > Forages & Forage Seed

No-Till Seeding of Annual Crops into Alfalfa/Grass Forages
Author: Dr. Mirza Baig and Peter Gamache
Date Created: April 02, 2007
Last Reviewed: April 02, 2007
Many growers in the Parkland region of western Canada practice diversified crop rotations that include perennial forages. A commonly used forage crop is alfalfa, although alfalfa/grass mixtures are also used. Typically forages are grown for 5 years before being terminated. Traditionally, intensive tillage has been used to remove forages from rotation and prepare a new seedbed before seeding an annual crop. This method is costly and time consuming and makes the soil susceptible to erosion and soil moisture loss. An alternative approach is to terminate an existing forage stand using herbicides before seeding annual crops into sod using direct seed drills with discs or narrow openers. This approach offers many benefits to the growers such as reduced soil erosion, energy inputs, and soil moisture conservation. Glyphosate is a broad-spectrum herbicide without any soil residues; it can be effectively used for the termination of perennial grass/legume forage stands before annual crops. Glyphosate applied at 1.35 – 1.8 kg a.i./ha applied pre-harvest to forage crops, 3 – 7 days prior to the last cut (August – September) before rotation to annual crops or forage renovation is a registered use. In western Canada, forage stands are often infested with quackgrass, Canada thistles, dandelions, winter annuals and other problem weeds at the time of termination. Pre-harvest applications of glyphosate control quackgrass, Canada thistle, perennial sow thistle, dandelions, and other perennial weeds (Crop Protection 2006: Alberta Agriculture, Food and Rural Development). In recent years, herbicide termination of forages prior to annual crops has become increasingly popular among Canadian growers. There are a few reports on this subject (Prochnau and Jensen 1995; Keng and Sprout 1998; Bullied et al 1999; Bullied and Entz 1999; Hutton 1999; Moyer et al 2003). The focus of this fact sheet is to provide the recommendations on no-till forage stand termination (sod seeding) based upon this research.  Click on the above pdf for the complete 6-page factsheet.